v13-0001-Transform-OR-clause-to-ANY-expressions.patch

From a5f8eba522ff907f7a3fffb0635b61d38933e385 Mon Sep 17 00:00:00 2001
From: "Andrey V. Lepikhov" <a.lepikhov@postgrespro.ru>
Date: Thu, 23 Nov 2023 16:00:13 +0700
Subject: [PATCH] Transform OR clause to ANY expressions.

Replace (X=N1) OR (X=N2) ... with X = ANY(N1, N2) on the preliminary stage of
optimization when we are still working with a tree expression.
Sometimes it can lead to not optimal plan. But we think it is better to have
array of elements instead of a lot of OR clauses. Here is a room for further
optimizations on decomposing that array into more optimal parts.
---
 .../postgres_fdw/expected/postgres_fdw.out    |   8 +-
 src/backend/nodes/queryjumblefuncs.c          |  30 ++
 src/backend/parser/parse_expr.c               | 289 +++++++++++++++++-
 src/backend/utils/misc/guc_tables.c           |  10 +
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/nodes/queryjumble.h               |   1 +
 src/include/parser/parse_expr.h               |   1 +
 src/test/regress/expected/create_index.out    | 141 +++++++--
 src/test/regress/expected/guc.out             |   3 +-
 src/test/regress/expected/inherit.out         |   2 +-
 src/test/regress/expected/join.out            |  62 +++-
 src/test/regress/expected/partition_join.out  |   2 +-
 src/test/regress/expected/partition_prune.out | 215 +++++++++++--
 src/test/regress/expected/rules.out           |   4 +-
 src/test/regress/expected/select.out          |   6 +-
 src/test/regress/expected/stats_ext.out       |  12 +-
 src/test/regress/expected/sysviews.out        |   3 +-
 src/test/regress/expected/tidscan.out         |  23 +-
 src/test/regress/sql/create_index.sql         |  32 ++
 src/test/regress/sql/join.sql                 |  10 +
 src/test/regress/sql/partition_prune.sql      |  22 ++
 src/test/regress/sql/tidscan.sql              |   6 +
 src/tools/pgindent/typedefs.list              |   2 +
 23 files changed, 819 insertions(+), 66 deletions(-)

diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 22cae37a1e..fdfecd51c7 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -8537,18 +8537,18 @@ insert into utrtest values (2, 'qux');
 -- Check case where the foreign partition is a subplan target rel
 explain (verbose, costs off)
 update utrtest set a = 1 where a = 1 or a = 2 returning *;
-                                             QUERY PLAN                                             
-----------------------------------------------------------------------------------------------------
+                                                  QUERY PLAN                                                  
+--------------------------------------------------------------------------------------------------------------
  Update on public.utrtest
    Output: utrtest_1.a, utrtest_1.b
    Foreign Update on public.remp utrtest_1
    Update on public.locp utrtest_2
    ->  Append
          ->  Foreign Update on public.remp utrtest_1
-               Remote SQL: UPDATE public.loct SET a = 1 WHERE (((a = 1) OR (a = 2))) RETURNING a, b
+               Remote SQL: UPDATE public.loct SET a = 1 WHERE ((a = ANY ('{1,2}'::integer[]))) RETURNING a, b
          ->  Seq Scan on public.locp utrtest_2
                Output: 1, utrtest_2.tableoid, utrtest_2.ctid, NULL::record
-               Filter: ((utrtest_2.a = 1) OR (utrtest_2.a = 2))
+               Filter: (utrtest_2.a = ANY ('{1,2}'::integer[]))
 (10 rows)
 
 -- The new values are concatenated with ' triggered !'
diff --git a/src/backend/nodes/queryjumblefuncs.c b/src/backend/nodes/queryjumblefuncs.c
index 281907a4d8..99207a8670 100644
--- a/src/backend/nodes/queryjumblefuncs.c
+++ b/src/backend/nodes/queryjumblefuncs.c
@@ -135,6 +135,36 @@ JumbleQuery(Query *query)
 	return jstate;
 }
 
+JumbleState *
+JumbleExpr(Expr *expr, uint64 *queryId)
+{
+	JumbleState *jstate = NULL;
+
+	Assert(queryId != NULL);
+
+	jstate = (JumbleState *) palloc(sizeof(JumbleState));
+
+	/* Set up workspace for query jumbling */
+	jstate->jumble = (unsigned char *) palloc(JUMBLE_SIZE);
+	jstate->jumble_len = 0;
+	jstate->clocations_buf_size = 32;
+	jstate->clocations = (LocationLen *)
+		palloc(jstate->clocations_buf_size * sizeof(LocationLen));
+	jstate->clocations_count = 0;
+	jstate->highest_extern_param_id = 0;
+
+	/* Compute query ID */
+	_jumbleNode(jstate, (Node *) expr);
+	*queryId = DatumGetUInt64(hash_any_extended(jstate->jumble,
+												jstate->jumble_len,
+												0));
+
+	if (*queryId == UINT64CONST(0))
+		*queryId = UINT64CONST(1);
+
+	return jstate;
+}
+
 /*
  * Enables query identifier computation.
  *
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 64c582c344..d8c6096144 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -16,12 +16,14 @@
 #include "postgres.h"
 
 #include "catalog/pg_aggregate.h"
+#include "catalog/pg_operator.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
 #include "nodes/nodeFuncs.h"
+#include "nodes/queryjumble.h"
 #include "optimizer/optimizer.h"
 #include "parser/analyze.h"
 #include "parser/parse_agg.h"
@@ -38,11 +40,13 @@
 #include "utils/date.h"
 #include "utils/fmgroids.h"
 #include "utils/lsyscache.h"
+#include "utils/syscache.h"
 #include "utils/timestamp.h"
 #include "utils/xml.h"
 
 /* GUC parameters */
 bool		Transform_null_equals = false;
+bool		enable_or_transformation = true;
 
 
 static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -99,6 +103,289 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
 static Node *make_nulltest_from_distinct(ParseState *pstate,
 										 A_Expr *distincta, Node *arg);
 
+typedef struct OrClauseGroupKey
+{
+	Expr   *expr; /* Pointer to the expression tree which has been a source for
+					the hashkey value */
+	Oid		opno;
+	Oid		exprtype;
+} OrClauseGroupKey;
+
+typedef struct OrClauseGroupEntry
+{
+	OrClauseGroupKey key;
+
+	Node		   *node;
+	List		   *consts;
+	Oid				scalar_type;
+	List 		   *exprs;
+} OrClauseGroupEntry;
+
+/*
+ * Hash function that's compatible with guc_name_compare
+ */
+static uint32
+orclause_hash(const void *data, Size keysize)
+{
+	OrClauseGroupKey   *key = (OrClauseGroupKey *) data;
+	uint64				hash;
+
+	(void) JumbleExpr(key->expr, &hash);
+	hash += ((uint64) key->opno + (uint64) key->exprtype) % UINT64_MAX;
+	return hash;
+}
+
+static void *
+orclause_keycopy(void *dest, const void *src, Size keysize)
+{
+	OrClauseGroupKey *src_key = (OrClauseGroupKey *) src;
+	OrClauseGroupKey *dst_key = (OrClauseGroupKey *) dest;
+
+	Assert(sizeof(OrClauseGroupKey) == keysize);
+
+	dst_key->expr = src_key->expr;
+	dst_key->opno = src_key->opno;
+	dst_key->exprtype = src_key->exprtype;
+	return dst_key;
+}
+
+/*
+ * Dynahash match function to use in guc_hashtab
+ */
+static int
+orclause_match(const void *data1, const void *data2, Size keysize)
+{
+	OrClauseGroupKey   *key1 = (OrClauseGroupKey *) data1;
+	OrClauseGroupKey   *key2 = (OrClauseGroupKey *) data2;
+
+	Assert(sizeof(OrClauseGroupKey) == keysize);
+
+	if (key1->opno == key2->opno && key1->exprtype == key2->exprtype &&
+		equal(key1->expr, key2->expr))
+		return 0;
+
+	return 1;
+}
+
+static Node *
+transformBoolExprOr(ParseState *pstate, BoolExpr *expr)
+{
+	List				   *or_list = NIL;
+	ListCell			   *lc;
+	HASHCTL					info;
+	HTAB 				   *or_group_htab = NULL;
+	int 					len_ors = list_length(expr->args);
+	HASH_SEQ_STATUS			hash_seq;
+	OrClauseGroupEntry	   *entry = NULL;
+
+	/* If this is not an 'OR' expression, skip the transformation */
+	if (!enable_or_transformation || expr->boolop != OR_EXPR || len_ors < 2)
+		return transformBoolExpr(pstate, (BoolExpr *) expr);
+
+	MemSet(&info, 0, sizeof(info));
+	info.keysize = sizeof(OrClauseGroupKey);
+	info.entrysize = sizeof(OrClauseGroupEntry);
+	info.hash = orclause_hash;
+	info.keycopy = orclause_keycopy;
+	info.match = orclause_match;
+	or_group_htab = hash_create("OR Groups",
+								len_ors,
+								&info,
+								HASH_ELEM | HASH_FUNCTION | HASH_COMPARE | HASH_KEYCOPY);
+
+	foreach(lc, expr->args)
+	{
+		Node				   *arg = lfirst(lc);
+		Node				   *orqual;
+		Node				   *const_expr;
+		Node				   *nconst_expr;
+		OrClauseGroupKey		hashkey;
+		bool					found;
+
+		/* At first, transform the arg and evaluate constant expressions. */
+		orqual = transformExprRecurse(pstate, (Node *) arg);
+		orqual = coerce_to_boolean(pstate, orqual, "OR");
+
+		if (!IsA(orqual, OpExpr))
+		{
+			or_list = lappend(or_list, orqual);
+			continue;
+		}
+
+		/*
+		 * Detect the constant side of the clause. Recall non-constant
+		 * expression can be made not only with Vars, but also with Params,
+		 * which is not bonded with any relation. Thus, we detect the const
+		 * side - if another side is constant too, the orqual couldn't be
+		 * an OpExpr.
+		 * Get pointers to constant and expression sides of the qual.
+		 */
+		if (IsA(get_leftop(orqual), Const))
+		{
+			nconst_expr = get_rightop(orqual);
+			const_expr = get_leftop(orqual);
+		}
+		else if (IsA(get_rightop(orqual), Const))
+		{
+			const_expr = get_rightop(orqual);
+			nconst_expr = get_leftop(orqual);
+		}
+		else
+		{
+			or_list = lappend(or_list, orqual);
+			continue;
+		}
+
+		if (!op_mergejoinable(((OpExpr *) orqual)->opno, exprType(nconst_expr)))
+		{
+			or_list = lappend(or_list, orqual);
+			continue;
+		}
+
+		/*
+		* At this point we definitely have a transformable clause.
+		* Classify it and add into specific group of clauses, or create new
+		* group.
+		* TODO: to manage complexity in the case of many different clauses
+		* (X1=C1) OR (X2=C2 OR) ... (XN = CN) we could invent something
+		* like a hash table. But also we believe, that the case of many
+		* different variable sides is very rare.
+		*/
+		hashkey.expr = (Expr *) nconst_expr;
+		hashkey.opno = ((OpExpr *) orqual)->opno;
+		hashkey.exprtype = exprType(nconst_expr);
+		entry = hash_search(or_group_htab, &hashkey, HASH_ENTER, &found);
+
+		if (unlikely(found))
+		{
+			entry->consts = lappend(entry->consts, const_expr);
+			entry->exprs = lappend(entry->exprs, orqual);
+		}
+		else
+		{
+			entry->node = nconst_expr;
+			entry->consts = list_make1(const_expr);
+			entry->exprs = list_make1(orqual);
+		}
+	}
+
+	if (list_length(or_list) == len_ors)
+	{
+		/*
+		* No any transformations possible with this list of arguments. Here we
+		* already made all underlying transformations. Thus, just return the
+		* transformed bool expression.
+		*/
+		hash_destroy(or_group_htab);
+		return (Node *) makeBoolExpr(OR_EXPR, or_list, expr->location);
+	}
+
+	hash_seq_init(&hash_seq, or_group_htab);
+
+	/* Let's convert each group of clauses to an IN operation. */
+
+	/*
+	 * Go through the list of groups and convert each, where number of
+	* consts more than 1. trivial groups move to OR-list again
+	*/
+
+	while ((entry = (OrClauseGroupEntry *) hash_seq_search(&hash_seq)) != NULL)
+	{
+		List			   *allexprs;
+		Oid				    scalar_type;
+		Oid					array_type;
+
+		Assert(list_length(entry->consts) > 0);
+		Assert(list_length(entry->exprs) == list_length(entry->consts));
+
+		if (list_length(entry->consts) == 1)
+		{
+			/*
+			 * Only one element in the class. Return rinfo into the BoolExpr
+			 * args list unchanged.
+			 */
+			list_free(entry->consts);
+			or_list = list_concat(or_list, entry->exprs);
+			continue;
+		}
+
+		/*
+		 * Do the transformation.
+		 */
+		allexprs = list_concat(list_make1(entry->node), entry->consts);
+		scalar_type = entry->key.exprtype;
+
+		if (scalar_type != RECORDOID && OidIsValid(scalar_type))
+			array_type = get_array_type(scalar_type);
+		else
+			array_type = InvalidOid;
+
+		if (array_type != InvalidOid)
+		{
+			/*
+			 * OK: coerce all the right-hand non-Var inputs to the common
+			 * type and build an ArrayExpr for them.
+			 */
+			List			   *aexprs = NIL;
+			ArrayExpr		   *newa = NULL;
+			ScalarArrayOpExpr  *saopexpr = NULL;
+			ListCell		   *l;
+			HeapTuple			opertup;
+			Form_pg_operator	operform;
+			List			   *namelist = NIL;
+
+			aexprs = entry->consts;
+
+			newa = makeNode(ArrayExpr);
+			/* array_collid will be set by parse_collate.c */
+			newa->element_typeid = scalar_type;
+			newa->array_typeid = array_type;
+			newa->multidims = false;
+			newa->elements = aexprs;
+			newa->location = -1;
+
+			opertup = SearchSysCache1(OPEROID,
+									  ObjectIdGetDatum(entry->key.opno));
+			if (!HeapTupleIsValid(opertup))
+				elog(ERROR, "cache lookup failed for operator %u",
+					 entry->key.opno);
+
+			operform = (Form_pg_operator) GETSTRUCT(opertup);
+			if (!OperatorIsVisible(entry->key.opno))
+				namelist = lappend(namelist, makeString(get_namespace_name(operform->oprnamespace)));
+
+			namelist = lappend(namelist, makeString(pstrdup(NameStr(operform->oprname))));
+			ReleaseSysCache(opertup);
+
+			saopexpr =
+				(ScalarArrayOpExpr *)
+					make_scalar_array_op(pstate,
+										 namelist,
+										 true,
+										 entry->node,
+										 (Node *) newa,
+										 -1);
+
+			or_list = lappend(or_list, (void *) saopexpr);
+		}
+		else
+		{
+			/*
+			 * This part works on intarray test (OR there is made on
+			 * elements of a custom type)
+			 */
+			list_free(entry->consts);
+			or_list = list_concat(or_list, entry->exprs);
+		}
+		hash_search(or_group_htab, &entry->key, HASH_REMOVE, NULL);
+	}
+	hash_destroy(or_group_htab);
+
+	/* One more trick: assemble correct clause */
+	return (Node *) ((list_length(or_list) > 1) ?
+					 makeBoolExpr(OR_EXPR, or_list, expr->location) :
+					 linitial(or_list));
+}
 
 /*
  * transformExpr -
@@ -212,7 +499,7 @@ transformExprRecurse(ParseState *pstate, Node *expr)
 			}
 
 		case T_BoolExpr:
-			result = transformBoolExpr(pstate, (BoolExpr *) expr);
+			result = transformBoolExprOr(pstate, (BoolExpr *) expr);
 			break;
 
 		case T_FuncCall:
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index b764ef6998..2ca8a21caf 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1048,6 +1048,16 @@ struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"enable_or_transformation", PGC_USERSET, QUERY_TUNING_OTHER,
+			gettext_noop("Transform a sequence of OR clauses to an IN expression."),
+			gettext_noop("The planner will replace clauses like 'x=c1 OR x=c2 .."
+						 "to the clause 'x IN (c1,c2,...)'")
+		},
+		&enable_or_transformation,
+		true,
+		NULL, NULL, NULL
+	},
 	{
 		/*
 		 * Not for general use --- used by SET SESSION AUTHORIZATION and SET
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e48c066a5b..26bee30ad3 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -371,6 +371,7 @@
 # - Planner Method Configuration -
 
 #enable_async_append = on
+#enable_or_transformation = on
 #enable_bitmapscan = on
 #enable_gathermerge = on
 #enable_hashagg = on
diff --git a/src/include/nodes/queryjumble.h b/src/include/nodes/queryjumble.h
index 0769081c7a..4aaa31aa80 100644
--- a/src/include/nodes/queryjumble.h
+++ b/src/include/nodes/queryjumble.h
@@ -65,6 +65,7 @@ extern PGDLLIMPORT int compute_query_id;
 
 extern const char *CleanQuerytext(const char *query, int *location, int *len);
 extern JumbleState *JumbleQuery(Query *query);
+extern JumbleState *JumbleExpr(Expr *expr, uint64 *queryId);
 extern void EnableQueryId(void);
 
 extern PGDLLIMPORT bool query_id_enabled;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 7d38ca75f7..3a87de0285 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
 
 /* GUC parameters */
 extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool enable_or_transformation;
 
 extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
 
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index acfd9d1f4f..3bb4bbca48 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -1838,18 +1838,50 @@ DROP TABLE onek_with_null;
 EXPLAIN (COSTS OFF)
 SELECT * FROM tenk1
   WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
-                                                               QUERY PLAN                                                                
------------------------------------------------------------------------------------------------------------------------------------------
- Bitmap Heap Scan on tenk1
-   Recheck Cond: (((thousand = 42) AND (tenthous = 1)) OR ((thousand = 42) AND (tenthous = 3)) OR ((thousand = 42) AND (tenthous = 42)))
-   ->  BitmapOr
-         ->  Bitmap Index Scan on tenk1_thous_tenthous
-               Index Cond: ((thousand = 42) AND (tenthous = 1))
-         ->  Bitmap Index Scan on tenk1_thous_tenthous
-               Index Cond: ((thousand = 42) AND (tenthous = 3))
-         ->  Bitmap Index Scan on tenk1_thous_tenthous
-               Index Cond: ((thousand = 42) AND (tenthous = 42))
-(9 rows)
+                                  QUERY PLAN                                  
+------------------------------------------------------------------------------
+ Index Scan using tenk1_thous_tenthous on tenk1
+   Index Cond: ((thousand = 42) AND (tenthous = ANY ('{1,3,42}'::integer[])))
+(2 rows)
+
+SELECT * FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+ unique1 | unique2 | two | four | ten | twenty | hundred | thousand | twothousand | fivethous | tenthous | odd | even | stringu1 | stringu2 | string4 
+---------+---------+-----+------+-----+--------+---------+----------+-------------+-----------+----------+-----+------+----------+----------+---------
+      42 |    5530 |   0 |    2 |   2 |      2 |      42 |       42 |          42 |        42 |       42 |  84 |   85 | QBAAAA   | SEIAAA   | OOOOxx
+(1 row)
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+                                     QUERY PLAN                                     
+------------------------------------------------------------------------------------
+ Aggregate
+   ->  Bitmap Heap Scan on tenk1
+         Recheck Cond: ((hundred = 42) AND (thousand = ANY ('{42,99}'::integer[])))
+         ->  BitmapAnd
+               ->  Bitmap Index Scan on tenk1_hundred
+                     Index Cond: (hundred = 42)
+               ->  Bitmap Index Scan on tenk1_thous_tenthous
+                     Index Cond: (thousand = ANY ('{42,99}'::integer[]))
+(8 rows)
+
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+ count 
+-------
+    10
+(1 row)
+
+SET enable_or_transformation = on;
+EXPLAIN (COSTS OFF)
+SELECT * FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+                                  QUERY PLAN                                  
+------------------------------------------------------------------------------
+ Index Scan using tenk1_thous_tenthous on tenk1
+   Index Cond: ((thousand = 42) AND (tenthous = ANY ('{1,3,42}'::integer[])))
+(2 rows)
 
 SELECT * FROM tenk1
   WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
@@ -1861,28 +1893,101 @@ SELECT * FROM tenk1
 EXPLAIN (COSTS OFF)
 SELECT count(*) FROM tenk1
   WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
-                                   QUERY PLAN                                    
----------------------------------------------------------------------------------
+                                     QUERY PLAN                                     
+------------------------------------------------------------------------------------
  Aggregate
    ->  Bitmap Heap Scan on tenk1
-         Recheck Cond: ((hundred = 42) AND ((thousand = 42) OR (thousand = 99)))
+         Recheck Cond: ((hundred = 42) AND (thousand = ANY ('{42,99}'::integer[])))
+         ->  BitmapAnd
+               ->  Bitmap Index Scan on tenk1_hundred
+                     Index Cond: (hundred = 42)
+               ->  Bitmap Index Scan on tenk1_thous_tenthous
+                     Index Cond: (thousand = ANY ('{42,99}'::integer[]))
+(8 rows)
+
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+ count 
+-------
+    10
+(1 row)
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3) OR thousand = 41;
+                                               QUERY PLAN                                               
+--------------------------------------------------------------------------------------------------------
+ Aggregate
+   ->  Bitmap Heap Scan on tenk1
+         Recheck Cond: (((thousand = 42) AND (tenthous = ANY ('{1,3}'::integer[]))) OR (thousand = 41))
+         ->  BitmapOr
+               ->  Bitmap Index Scan on tenk1_thous_tenthous
+                     Index Cond: ((thousand = 42) AND (tenthous = ANY ('{1,3}'::integer[])))
+               ->  Bitmap Index Scan on tenk1_thous_tenthous
+                     Index Cond: (thousand = 41)
+(8 rows)
+
+SELECT count(*) FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3) OR thousand = 41;
+ count 
+-------
+    10
+(1 row)
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99 OR tenthous < 2) OR thousand = 41;
+                                                         QUERY PLAN                                                          
+-----------------------------------------------------------------------------------------------------------------------------
+ Aggregate
+   ->  Bitmap Heap Scan on tenk1
+         Recheck Cond: (((hundred = 42) AND ((tenthous < 2) OR (thousand = ANY ('{42,99}'::integer[])))) OR (thousand = 41))
+         ->  BitmapOr
+               ->  BitmapAnd
+                     ->  Bitmap Index Scan on tenk1_hundred
+                           Index Cond: (hundred = 42)
+                     ->  BitmapOr
+                           ->  Bitmap Index Scan on tenk1_thous_tenthous
+                                 Index Cond: (tenthous < 2)
+                           ->  Bitmap Index Scan on tenk1_thous_tenthous
+                                 Index Cond: (thousand = ANY ('{42,99}'::integer[]))
+               ->  Bitmap Index Scan on tenk1_thous_tenthous
+                     Index Cond: (thousand = 41)
+(14 rows)
+
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99 OR tenthous < 2) OR thousand = 41;
+ count 
+-------
+    20
+(1 row)
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 41 OR thousand = 99 AND tenthous = 2);
+                                                          QUERY PLAN                                                          
+------------------------------------------------------------------------------------------------------------------------------
+ Aggregate
+   ->  Bitmap Heap Scan on tenk1
+         Recheck Cond: ((hundred = 42) AND (((thousand = 99) AND (tenthous = 2)) OR (thousand = ANY ('{42,41}'::integer[]))))
          ->  BitmapAnd
                ->  Bitmap Index Scan on tenk1_hundred
                      Index Cond: (hundred = 42)
                ->  BitmapOr
                      ->  Bitmap Index Scan on tenk1_thous_tenthous
-                           Index Cond: (thousand = 42)
+                           Index Cond: ((thousand = 99) AND (tenthous = 2))
                      ->  Bitmap Index Scan on tenk1_thous_tenthous
-                           Index Cond: (thousand = 99)
+                           Index Cond: (thousand = ANY ('{42,41}'::integer[]))
 (11 rows)
 
 SELECT count(*) FROM tenk1
-  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 41 OR thousand = 99 AND tenthous = 2);
  count 
 -------
     10
 (1 row)
 
+RESET enable_or_transformation;
 --
 -- Check behavior with duplicate index column contents
 --
diff --git a/src/test/regress/expected/guc.out b/src/test/regress/expected/guc.out
index 127c953297..0f2b1b1620 100644
--- a/src/test/regress/expected/guc.out
+++ b/src/test/regress/expected/guc.out
@@ -861,7 +861,8 @@ SELECT name FROM tab_settings_flags
            name            
 ---------------------------
  default_statistics_target
-(1 row)
+ enable_or_transformation
+(2 rows)
 
 -- Runtime-computed GUCs should be part of the preset category.
 SELECT name FROM tab_settings_flags
diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out
index 0f1aa831f6..1781250122 100644
--- a/src/test/regress/expected/inherit.out
+++ b/src/test/regress/expected/inherit.out
@@ -2560,7 +2560,7 @@ explain (costs off) select * from list_parted where a = 'ab' or a in (null, 'cd'
                                    QUERY PLAN                                    
 ---------------------------------------------------------------------------------
  Seq Scan on part_ab_cd list_parted
-   Filter: (((a)::text = 'ab'::text) OR ((a)::text = ANY ('{NULL,cd}'::text[])))
+   Filter: (((a)::text = ANY ('{NULL,cd}'::text[])) OR ((a)::text = 'ab'::text))
 (2 rows)
 
 explain (costs off) select * from list_parted where a = 'ab';
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 2c73270143..e952e5401f 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -4210,10 +4210,10 @@ explain (costs off)
 select * from tenk1 a join tenk1 b on
   (a.unique1 = 1 and b.unique1 = 2) or
   ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
-                                                      QUERY PLAN                                                      
-----------------------------------------------------------------------------------------------------------------------
+                                                       QUERY PLAN                                                       
+------------------------------------------------------------------------------------------------------------------------
  Nested Loop
-   Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR (((a.unique2 = 3) OR (a.unique2 = 7)) AND (b.hundred = 4)))
+   Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR ((a.unique2 = ANY ('{3,7}'::integer[])) AND (b.hundred = 4)))
    ->  Bitmap Heap Scan on tenk1 b
          Recheck Cond: ((unique1 = 2) OR (hundred = 4))
          ->  BitmapOr
@@ -4223,16 +4223,64 @@ select * from tenk1 a join tenk1 b on
                      Index Cond: (hundred = 4)
    ->  Materialize
          ->  Bitmap Heap Scan on tenk1 a
-               Recheck Cond: ((unique1 = 1) OR (unique2 = 3) OR (unique2 = 7))
+               Recheck Cond: ((unique1 = 1) OR (unique2 = ANY ('{3,7}'::integer[])))
                ->  BitmapOr
                      ->  Bitmap Index Scan on tenk1_unique1
                            Index Cond: (unique1 = 1)
                      ->  Bitmap Index Scan on tenk1_unique2
-                           Index Cond: (unique2 = 3)
+                           Index Cond: (unique2 = ANY ('{3,7}'::integer[]))
+(17 rows)
+
+SET enable_or_transformation = on;
+explain (costs off)
+select * from tenk1 a join tenk1 b on
+  (a.unique1 = 1 and b.unique1 = 2) or
+  ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+                                                       QUERY PLAN                                                       
+------------------------------------------------------------------------------------------------------------------------
+ Nested Loop
+   Join Filter: (((a.unique1 = 1) AND (b.unique1 = 2)) OR ((a.unique2 = ANY ('{3,7}'::integer[])) AND (b.hundred = 4)))
+   ->  Bitmap Heap Scan on tenk1 b
+         Recheck Cond: ((unique1 = 2) OR (hundred = 4))
+         ->  BitmapOr
+               ->  Bitmap Index Scan on tenk1_unique1
+                     Index Cond: (unique1 = 2)
+               ->  Bitmap Index Scan on tenk1_hundred
+                     Index Cond: (hundred = 4)
+   ->  Materialize
+         ->  Bitmap Heap Scan on tenk1 a
+               Recheck Cond: ((unique1 = 1) OR (unique2 = ANY ('{3,7}'::integer[])))
+               ->  BitmapOr
+                     ->  Bitmap Index Scan on tenk1_unique1
+                           Index Cond: (unique1 = 1)
                      ->  Bitmap Index Scan on tenk1_unique2
-                           Index Cond: (unique2 = 7)
-(19 rows)
+                           Index Cond: (unique2 = ANY ('{3,7}'::integer[]))
+(17 rows)
+
+explain (costs off)
+select * from tenk1 a join tenk1 b on
+  (a.unique1 < 20 or a.unique1 = 3 or a.unique1 = 1 and b.unique1 = 2) or
+  ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+                                                                          QUERY PLAN                                                                           
+---------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Nested Loop
+   Join Filter: ((a.unique1 < 20) OR ((a.unique1 = 1) AND (b.unique1 = 2)) OR ((a.unique2 = ANY ('{3,7}'::integer[])) AND (b.hundred = 4)) OR (a.unique1 = 3))
+   ->  Seq Scan on tenk1 b
+   ->  Materialize
+         ->  Bitmap Heap Scan on tenk1 a
+               Recheck Cond: ((unique1 < 20) OR (unique1 = 1) OR (unique2 = ANY ('{3,7}'::integer[])) OR (unique1 = 3))
+               ->  BitmapOr
+                     ->  Bitmap Index Scan on tenk1_unique1
+                           Index Cond: (unique1 < 20)
+                     ->  Bitmap Index Scan on tenk1_unique1
+                           Index Cond: (unique1 = 1)
+                     ->  Bitmap Index Scan on tenk1_unique2
+                           Index Cond: (unique2 = ANY ('{3,7}'::integer[]))
+                     ->  Bitmap Index Scan on tenk1_unique1
+                           Index Cond: (unique1 = 3)
+(15 rows)
 
+RESET enable_or_transformation;
 --
 -- test placement of movable quals in a parameterized join tree
 --
diff --git a/src/test/regress/expected/partition_join.out b/src/test/regress/expected/partition_join.out
index 6560fe2416..6e8d64655b 100644
--- a/src/test/regress/expected/partition_join.out
+++ b/src/test/regress/expected/partition_join.out
@@ -296,7 +296,7 @@ SELECT t1.a, t1.c, t2.b, t2.c FROM (SELECT * FROM prt1 WHERE a < 450) t1 FULL JO
    Sort Key: prt1.a, prt2.b
    ->  Hash Full Join
          Hash Cond: (prt1.a = prt2.b)
-         Filter: ((prt1.b = 0) OR (prt2.a = 0))
+         Filter: ((prt2.a = 0) OR (prt1.b = 0))
          ->  Append
                ->  Seq Scan on prt1_p1 prt1_1
                      Filter: (a < 450)
diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index 9a4c48c055..14a254fba7 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -82,25 +82,47 @@ explain (costs off) select * from lp where a is null;
 (2 rows)
 
 explain (costs off) select * from lp where a = 'a' or a = 'c';
-                        QUERY PLAN                        
-----------------------------------------------------------
+                  QUERY PLAN                   
+-----------------------------------------------
  Append
    ->  Seq Scan on lp_ad lp_1
-         Filter: ((a = 'a'::bpchar) OR (a = 'c'::bpchar))
+         Filter: (a = ANY ('{a,c}'::bpchar[]))
    ->  Seq Scan on lp_bc lp_2
-         Filter: ((a = 'a'::bpchar) OR (a = 'c'::bpchar))
+         Filter: (a = ANY ('{a,c}'::bpchar[]))
 (5 rows)
 
 explain (costs off) select * from lp where a is not null and (a = 'a' or a = 'c');
-                                   QUERY PLAN                                   
---------------------------------------------------------------------------------
+                             QUERY PLAN                              
+---------------------------------------------------------------------
  Append
    ->  Seq Scan on lp_ad lp_1
-         Filter: ((a IS NOT NULL) AND ((a = 'a'::bpchar) OR (a = 'c'::bpchar)))
+         Filter: ((a IS NOT NULL) AND (a = ANY ('{a,c}'::bpchar[])))
    ->  Seq Scan on lp_bc lp_2
-         Filter: ((a IS NOT NULL) AND ((a = 'a'::bpchar) OR (a = 'c'::bpchar)))
+         Filter: ((a IS NOT NULL) AND (a = ANY ('{a,c}'::bpchar[])))
 (5 rows)
 
+SET enable_or_transformation = on;
+explain (costs off) select * from lp where a = 'a' or a = 'c';
+                  QUERY PLAN                   
+-----------------------------------------------
+ Append
+   ->  Seq Scan on lp_ad lp_1
+         Filter: (a = ANY ('{a,c}'::bpchar[]))
+   ->  Seq Scan on lp_bc lp_2
+         Filter: (a = ANY ('{a,c}'::bpchar[]))
+(5 rows)
+
+explain (costs off) select * from lp where a is not null and (a = 'a' or a = 'c');
+                             QUERY PLAN                              
+---------------------------------------------------------------------
+ Append
+   ->  Seq Scan on lp_ad lp_1
+         Filter: ((a IS NOT NULL) AND (a = ANY ('{a,c}'::bpchar[])))
+   ->  Seq Scan on lp_bc lp_2
+         Filter: ((a IS NOT NULL) AND (a = ANY ('{a,c}'::bpchar[])))
+(5 rows)
+
+RESET enable_or_transformation;
 explain (costs off) select * from lp where a <> 'g';
              QUERY PLAN             
 ------------------------------------
@@ -515,10 +537,10 @@ explain (costs off) select * from rlp where a <= 31;
 (27 rows)
 
 explain (costs off) select * from rlp where a = 1 or a = 7;
-           QUERY PLAN           
---------------------------------
+                QUERY PLAN                
+------------------------------------------
  Seq Scan on rlp2 rlp
-   Filter: ((a = 1) OR (a = 7))
+   Filter: (a = ANY ('{1,7}'::integer[]))
 (2 rows)
 
 explain (costs off) select * from rlp where a = 1 or b = 'ab';
@@ -596,13 +618,13 @@ explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25);
 
 -- where clause contradicts sub-partition's constraint
 explain (costs off) select * from rlp where a = 20 or a = 40;
-               QUERY PLAN               
-----------------------------------------
+                    QUERY PLAN                    
+--------------------------------------------------
  Append
    ->  Seq Scan on rlp4_1 rlp_1
-         Filter: ((a = 20) OR (a = 40))
+         Filter: (a = ANY ('{20,40}'::integer[]))
    ->  Seq Scan on rlp5_default rlp_2
-         Filter: ((a = 20) OR (a = 40))
+         Filter: (a = ANY ('{20,40}'::integer[]))
 (5 rows)
 
 explain (costs off) select * from rlp3 where a = 20;   /* empty */
@@ -671,6 +693,163 @@ explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a =
          Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
 (11 rows)
 
+SET enable_or_transformation = on;
+explain (costs off) select * from rlp where a = 1 or a = 7;
+                QUERY PLAN                
+------------------------------------------
+ Seq Scan on rlp2 rlp
+   Filter: (a = ANY ('{1,7}'::integer[]))
+(2 rows)
+
+explain (costs off) select * from rlp where a = 1 or b = 'ab';
+                      QUERY PLAN                       
+-------------------------------------------------------
+ Append
+   ->  Seq Scan on rlp1 rlp_1
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp2 rlp_2
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp3abcd rlp_3
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp4_1 rlp_4
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp4_2 rlp_5
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp4_default rlp_6
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp5_1 rlp_7
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp5_default rlp_8
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp_default_10 rlp_9
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp_default_30 rlp_10
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp_default_null rlp_11
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+   ->  Seq Scan on rlp_default_default rlp_12
+         Filter: ((a = 1) OR ((b)::text = 'ab'::text))
+(25 rows)
+
+explain (costs off) select * from rlp where a > 20 and a < 27;
+               QUERY PLAN                
+-----------------------------------------
+ Append
+   ->  Seq Scan on rlp4_1 rlp_1
+         Filter: ((a > 20) AND (a < 27))
+   ->  Seq Scan on rlp4_2 rlp_2
+         Filter: ((a > 20) AND (a < 27))
+(5 rows)
+
+explain (costs off) select * from rlp where a = 29;
+          QUERY PLAN          
+------------------------------
+ Seq Scan on rlp4_default rlp
+   Filter: (a = 29)
+(2 rows)
+
+explain (costs off) select * from rlp where a >= 29;
+                 QUERY PLAN                  
+---------------------------------------------
+ Append
+   ->  Seq Scan on rlp4_default rlp_1
+         Filter: (a >= 29)
+   ->  Seq Scan on rlp5_1 rlp_2
+         Filter: (a >= 29)
+   ->  Seq Scan on rlp5_default rlp_3
+         Filter: (a >= 29)
+   ->  Seq Scan on rlp_default_30 rlp_4
+         Filter: (a >= 29)
+   ->  Seq Scan on rlp_default_default rlp_5
+         Filter: (a >= 29)
+(11 rows)
+
+explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25);
+                      QUERY PLAN                      
+------------------------------------------------------
+ Append
+   ->  Seq Scan on rlp1 rlp_1
+         Filter: ((a < 1) OR ((a > 20) AND (a < 25)))
+   ->  Seq Scan on rlp4_1 rlp_2
+         Filter: ((a < 1) OR ((a > 20) AND (a < 25)))
+(5 rows)
+
+explain (costs off) select * from rlp where a = 20 or a = 40;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Append
+   ->  Seq Scan on rlp4_1 rlp_1
+         Filter: (a = ANY ('{20,40}'::integer[]))
+   ->  Seq Scan on rlp5_default rlp_2
+         Filter: (a = ANY ('{20,40}'::integer[]))
+(5 rows)
+
+explain (costs off) select * from rlp3 where a = 20;   /* empty */
+        QUERY PLAN        
+--------------------------
+ Result
+   One-Time Filter: false
+(2 rows)
+
+explain (costs off) select * from rlp where a > 1 and a = 10;	/* only default */
+            QUERY PLAN            
+----------------------------------
+ Seq Scan on rlp_default_10 rlp
+   Filter: ((a > 1) AND (a = 10))
+(2 rows)
+
+explain (costs off) select * from rlp where a > 1 and a >=15;	/* rlp3 onwards, including default */
+                  QUERY PLAN                  
+----------------------------------------------
+ Append
+   ->  Seq Scan on rlp3abcd rlp_1
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp3efgh rlp_2
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp3nullxy rlp_3
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp3_default rlp_4
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp4_1 rlp_5
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp4_2 rlp_6
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp4_default rlp_7
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp5_1 rlp_8
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp5_default rlp_9
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp_default_30 rlp_10
+         Filter: ((a > 1) AND (a >= 15))
+   ->  Seq Scan on rlp_default_default rlp_11
+         Filter: ((a > 1) AND (a >= 15))
+(23 rows)
+
+explain (costs off) select * from rlp where a = 1 and a = 3;	/* empty */
+        QUERY PLAN        
+--------------------------
+ Result
+   One-Time Filter: false
+(2 rows)
+
+explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a = 15);
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Append
+   ->  Seq Scan on rlp2 rlp_1
+         Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+   ->  Seq Scan on rlp3abcd rlp_2
+         Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+   ->  Seq Scan on rlp3efgh rlp_3
+         Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+   ->  Seq Scan on rlp3nullxy rlp_4
+         Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+   ->  Seq Scan on rlp3_default rlp_5
+         Filter: (((a = 1) AND (a = 3)) OR ((a > 1) AND (a = 15)))
+(11 rows)
+
+RESET enable_or_transformation;
 -- multi-column keys
 create table mc3p (a int, b int, c int) partition by range (a, abs(b), c);
 create table mc3p_default partition of mc3p default;
@@ -1933,10 +2112,10 @@ explain (costs off) select * from hp where a = 1 and b = 'abcde';
 
 explain (costs off) select * from hp where a = 1 and b = 'abcde' and
   (c = 2 or c = 3);
-                              QUERY PLAN                              
-----------------------------------------------------------------------
+                                   QUERY PLAN                                   
+--------------------------------------------------------------------------------
  Seq Scan on hp2 hp
-   Filter: ((a = 1) AND (b = 'abcde'::text) AND ((c = 2) OR (c = 3)))
+   Filter: ((c = ANY ('{2,3}'::integer[])) AND (a = 1) AND (b = 'abcde'::text))
 (2 rows)
 
 drop table hp2;
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 05070393b9..c927c21dd4 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2495,7 +2495,7 @@ pg_stats| SELECT n.nspname AS schemaname,
      JOIN pg_class c ON ((c.oid = s.starelid)))
      JOIN pg_attribute a ON (((c.oid = a.attrelid) AND (a.attnum = s.staattnum))))
      LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
-  WHERE ((NOT a.attisdropped) AND has_column_privilege(c.oid, a.attnum, 'select'::text) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
+  WHERE ((NOT a.attisdropped) AND has_column_privilege(c.oid, a.attnum, 'select'::text) AND ((NOT row_security_active(c.oid)) OR (c.relrowsecurity = false)));
 pg_stats_ext| SELECT cn.nspname AS schemaname,
     c.relname AS tablename,
     sn.nspname AS statistics_schemaname,
@@ -2526,7 +2526,7 @@ pg_stats_ext| SELECT cn.nspname AS schemaname,
   WHERE ((NOT (EXISTS ( SELECT 1
            FROM (unnest(s.stxkeys) k(k)
              JOIN pg_attribute a ON (((a.attrelid = s.stxrelid) AND (a.attnum = k.k))))
-          WHERE (NOT has_column_privilege(c.oid, a.attnum, 'select'::text))))) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
+          WHERE (NOT has_column_privilege(c.oid, a.attnum, 'select'::text))))) AND ((NOT row_security_active(c.oid)) OR (c.relrowsecurity = false)));
 pg_stats_ext_exprs| SELECT cn.nspname AS schemaname,
     c.relname AS tablename,
     sn.nspname AS statistics_schemaname,
diff --git a/src/test/regress/expected/select.out b/src/test/regress/expected/select.out
index 33a6dceb0e..7a829c44c7 100644
--- a/src/test/regress/expected/select.out
+++ b/src/test/regress/expected/select.out
@@ -868,13 +868,13 @@ select unique1, unique2 from onek2
                                    QUERY PLAN                                   
 --------------------------------------------------------------------------------
  Bitmap Heap Scan on onek2
-   Recheck Cond: (((unique2 = 11) AND (stringu1 < 'B'::name)) OR (unique1 = 0))
+   Recheck Cond: ((unique1 = 0) OR ((unique2 = 11) AND (stringu1 < 'B'::name)))
    Filter: (stringu1 < 'B'::name)
    ->  BitmapOr
-         ->  Bitmap Index Scan on onek2_u2_prtl
-               Index Cond: (unique2 = 11)
          ->  Bitmap Index Scan on onek2_u1_prtl
                Index Cond: (unique1 = 0)
+         ->  Bitmap Index Scan on onek2_u2_prtl
+               Index Cond: (unique2 = 11)
 (8 rows)
 
 select unique1, unique2 from onek2
diff --git a/src/test/regress/expected/stats_ext.out b/src/test/regress/expected/stats_ext.out
index a430153b22..659d712f75 100644
--- a/src/test/regress/expected/stats_ext.out
+++ b/src/test/regress/expected/stats_ext.out
@@ -1322,19 +1322,19 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND b = ''1''');
  estimated | actual 
 -----------+--------
-        99 |    100
+       100 |    100
 (1 row)
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND (b = ''1'' OR b = ''2'')');
  estimated | actual 
 -----------+--------
-        99 |    100
+       100 |    100
 (1 row)
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 2 OR a = 51 OR a = 52) AND (b = ''1'' OR b = ''2'')');
  estimated | actual 
 -----------+--------
-       197 |    200
+       200 |    200
 (1 row)
 
 -- OR clauses referencing different attributes are incompatible
@@ -1664,19 +1664,19 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 102) AND upper(b) = ''1''');
  estimated | actual 
 -----------+--------
-        99 |    100
+       100 |    100
 (1 row)
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 102) AND (upper(b) = ''1'' OR upper(b) = ''2'')');
  estimated | actual 
 -----------+--------
-        99 |    100
+       100 |    100
 (1 row)
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 4 OR (a * 2) = 102 OR (a * 2) = 104) AND (upper(b) = ''1'' OR upper(b) = ''2'')');
  estimated | actual 
 -----------+--------
-       197 |    200
+       200 |    200
 (1 row)
 
 -- OR clauses referencing different attributes
diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out
index 271313ebf8..c6c6b9fb8d 100644
--- a/src/test/regress/expected/sysviews.out
+++ b/src/test/regress/expected/sysviews.out
@@ -123,6 +123,7 @@ select name, setting from pg_settings where name like 'enable%';
  enable_memoize                 | on
  enable_mergejoin               | on
  enable_nestloop                | on
+ enable_or_transformation       | on
  enable_parallel_append         | on
  enable_parallel_hash           | on
  enable_partition_pruning       | on
@@ -133,7 +134,7 @@ select name, setting from pg_settings where name like 'enable%';
  enable_seqscan                 | on
  enable_sort                    | on
  enable_tidscan                 | on
-(22 rows)
+(23 rows)
 
 -- There are always wait event descriptions for various types.
 select type, count(*) > 0 as ok FROM pg_wait_events
diff --git a/src/test/regress/expected/tidscan.out b/src/test/regress/expected/tidscan.out
index f133b5a4ac..2a079e996b 100644
--- a/src/test/regress/expected/tidscan.out
+++ b/src/test/regress/expected/tidscan.out
@@ -43,10 +43,26 @@ SELECT ctid, * FROM tidscan WHERE '(0,1)' = ctid;
 -- OR'd clauses
 EXPLAIN (COSTS OFF)
 SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
-                          QUERY PLAN                          
---------------------------------------------------------------
+                      QUERY PLAN                       
+-------------------------------------------------------
+ Tid Scan on tidscan
+   TID Cond: (ctid = ANY ('{"(0,2)","(0,1)"}'::tid[]))
+(2 rows)
+
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+ ctid  | id 
+-------+----
+ (0,1) |  1
+ (0,2) |  2
+(2 rows)
+
+SET enable_or_transformation = on;
+EXPLAIN (COSTS OFF)
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+                      QUERY PLAN                       
+-------------------------------------------------------
  Tid Scan on tidscan
-   TID Cond: ((ctid = '(0,2)'::tid) OR ('(0,1)'::tid = ctid))
+   TID Cond: (ctid = ANY ('{"(0,2)","(0,1)"}'::tid[]))
 (2 rows)
 
 SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
@@ -56,6 +72,7 @@ SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
  (0,2) |  2
 (2 rows)
 
+RESET enable_or_transformation;
 -- ctid = ScalarArrayOp - implemented as tidscan
 EXPLAIN (COSTS OFF)
 SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]);
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index d49ce9f300..48bb1bc0a0 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -737,6 +737,38 @@ SELECT count(*) FROM tenk1
 SELECT count(*) FROM tenk1
   WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
 
+SET enable_or_transformation = on;
+EXPLAIN (COSTS OFF)
+SELECT * FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+SELECT * FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3 OR tenthous = 42);
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99);
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3) OR thousand = 41;
+SELECT count(*) FROM tenk1
+  WHERE thousand = 42 AND (tenthous = 1 OR tenthous = 3) OR thousand = 41;
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99 OR tenthous < 2) OR thousand = 41;
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 99 OR tenthous < 2) OR thousand = 41;
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 41 OR thousand = 99 AND tenthous = 2);
+SELECT count(*) FROM tenk1
+  WHERE hundred = 42 AND (thousand = 42 OR thousand = 41 OR thousand = 99 AND tenthous = 2);
+RESET enable_or_transformation;
+
 --
 -- Check behavior with duplicate index column contents
 --
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 8a8a63bd2f..55d7e2ae7d 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -1408,6 +1408,16 @@ explain (costs off)
 select * from tenk1 a join tenk1 b on
   (a.unique1 = 1 and b.unique1 = 2) or
   ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+SET enable_or_transformation = on;
+explain (costs off)
+select * from tenk1 a join tenk1 b on
+  (a.unique1 = 1 and b.unique1 = 2) or
+  ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+explain (costs off)
+select * from tenk1 a join tenk1 b on
+  (a.unique1 < 20 or a.unique1 = 3 or a.unique1 = 1 and b.unique1 = 2) or
+  ((a.unique2 = 3 or a.unique2 = 7) and b.hundred = 4);
+RESET enable_or_transformation;
 
 --
 -- test placement of movable quals in a parameterized join tree
diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index 7bf3920827..1e270ae9c0 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -21,6 +21,12 @@ explain (costs off) select * from lp where a is not null;
 explain (costs off) select * from lp where a is null;
 explain (costs off) select * from lp where a = 'a' or a = 'c';
 explain (costs off) select * from lp where a is not null and (a = 'a' or a = 'c');
+
+SET enable_or_transformation = on;
+explain (costs off) select * from lp where a = 'a' or a = 'c';
+explain (costs off) select * from lp where a is not null and (a = 'a' or a = 'c');
+RESET enable_or_transformation;
+
 explain (costs off) select * from lp where a <> 'g';
 explain (costs off) select * from lp where a <> 'a' and a <> 'd';
 explain (costs off) select * from lp where a not in ('a', 'd');
@@ -99,6 +105,22 @@ explain (costs off) select * from rlp where a > 1 and a >=15;	/* rlp3 onwards, i
 explain (costs off) select * from rlp where a = 1 and a = 3;	/* empty */
 explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a = 15);
 
+
+SET enable_or_transformation = on;
+explain (costs off) select * from rlp where a = 1 or a = 7;
+explain (costs off) select * from rlp where a = 1 or b = 'ab';
+explain (costs off) select * from rlp where a > 20 and a < 27;
+explain (costs off) select * from rlp where a = 29;
+explain (costs off) select * from rlp where a >= 29;
+explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25);
+explain (costs off) select * from rlp where a = 20 or a = 40;
+explain (costs off) select * from rlp3 where a = 20;   /* empty */
+explain (costs off) select * from rlp where a > 1 and a = 10;	/* only default */
+explain (costs off) select * from rlp where a > 1 and a >=15;	/* rlp3 onwards, including default */
+explain (costs off) select * from rlp where a = 1 and a = 3;	/* empty */
+explain (costs off) select * from rlp where (a = 1 and a = 3) or (a > 1 and a = 15);
+RESET enable_or_transformation;
+
 -- multi-column keys
 create table mc3p (a int, b int, c int) partition by range (a, abs(b), c);
 create table mc3p_default partition of mc3p default;
diff --git a/src/test/regress/sql/tidscan.sql b/src/test/regress/sql/tidscan.sql
index 313e0fb9b6..0499bedb9e 100644
--- a/src/test/regress/sql/tidscan.sql
+++ b/src/test/regress/sql/tidscan.sql
@@ -22,6 +22,12 @@ EXPLAIN (COSTS OFF)
 SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
 SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
 
+SET enable_or_transformation = on;
+EXPLAIN (COSTS OFF)
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+SELECT ctid, * FROM tidscan WHERE ctid = '(0,2)' OR '(0,1)' = ctid;
+RESET enable_or_transformation;
+
 -- ctid = ScalarArrayOp - implemented as tidscan
 EXPLAIN (COSTS OFF)
 SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]);
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 86a9886d4f..d9a7d9c284 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1642,6 +1642,8 @@ NumericVar
 OM_uint32
 OP
 OSAPerGroupState
+OrClauseGroupEntry
+OrClauseGroupKey
 OSAPerQueryState
 OSInfo
 OSSLCipher
-- 
2.43.0